ATI Super Damper Crank Pulley for EJ WRX/STi (917991)

The ATI Super Damper crankshaft pulley for EJ WRX and STi is suitable for high power street and race use. Direct replacement for the stock OEM damper. The damper's outer diameter is 5.5' making it a 5% overdriven pulley.

Unlike undampened underdrive pulleys, which offer no protection to high performance engines, the ATI Super Damper provides balanced dampening of torsional crankshaft vibrations at all RPM levels. The ATI Super Damper comes with laser-etched timing marks and is a direct replacement for the OEM unit.

The ATI Super Damper is a critical component for all high performance cars to help protect against engine harmonics and features four-groove and five-groove serpentine belt drives on the outer shell to utilize the factory serpentine belt set-up. All ATI Super Dampers exceed SFI 18.1 Safety Certification and are approved for competition use.

Vehicle Fitment:
2002-2014 Subaru WRX
2004-2021 Subaru STi

Features:
• High horsepower street & race use
• Dampens torsional crankshaft vibrations at all RPM levels
• Protects against engine harmonics
• Direct replacement for the OEM unit
• Four-rib and five-rib serpentine belt drives
• 5% Overdriven
• Utilizes factory serpentine belt set-up
• Laser-etched timing marks
• SFI 18.1 Safety Certification and are approved for competition use

Specs:
• Shell Material: Aluminum, Part #916883 5% Overdriven
• Hub Material: Steel, Part #916884
• Inertia Weight: 2.2 LBS, 3-Ring